我有不同的表像使用多個表獲取數據連接
Student primary id , students name, course Papers paper id, papername, course, semester, type StudentOptions primary id, studentid (foreign key - reference student id) and paperid (foreign key - references paper id) StudentsTerm studentid (foreign key- references student id) and student semester
現在的那種結果,我想是的,
我想選擇一門課程,然後術語,這將給我論文的數量/主題與其類型(強制/可選)以及我希望從所有這些表中學習這些論文的學生人數。
我不想創建任何視圖或東西,只是一個正常的選擇查詢會做。
我運行的查詢是:
SELECT p_name,
p_id,
type,
Count(sps.studentid) AS counts
FROM students,
str,
papers
LEFT JOIN sps
ON sps.paperid = papers.p_id
WHERE sps.studentid = students.studentid
AND students.studentid = str.studentid
AND sps.studentid = str.studentid
AND str.semesterid = p_semid
AND str.sessionid = 12
AND students.course = c_id
AND c_id = 6
AND p_semid = 1
GROUP BY p_id
感謝您的幫助提前。
你目前的查詢返回什麼?什麼不工作? – Msonic
它只給我那些學生正在學習的論文。我希望所有給定的學期和課程的論文,如果沒有任何學習,那麼它應該給我零。 –